NICHD sponsored and coordinated the 1988 survey to provide population- based data on children's health. Early work focused on effects of low birth weight and maternal smoking on children's later health status. The later work has analyzed childhood injury risk factors to support effective targeting of interventions since injury is the leading cause of death for children in the U.S. This is the first study to demonstrate that non-fatal injury causes differed considerably from fatal causes, with considerable variation of risk factors by age and socioeconomic characteristics. Analysis of injuries in preschool children by child care patterns showed that use of non-guardian care did not increase risks except for the youngest children of poor, low education mothers who use multiple part-time places of care of all types (center-based, care in their own home or homes of others). Increasing hours in center-based care seemed to lower both total and serious injury risks for children ages 4-5 years. Also, older children of women who are problem drinkers, or of two parents who are both problem drinkers, are at higher injury risk. Another risk factor analysis showed that sports and recreation account for 36% of all medically attended injuries from all causes. Analysis of effects of access to medical care showed that for children without medical care coverage (health insurance or Medicaid), as much as 30% of total injuries and 40% of serious injuries may not have received medical attention compared to children with medical care coverage. The latest studies have shown that children in single adult households are at increased risk regardless of other factors such as poverty or race.